using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

public class InterfaceExtends
{
	public static void Main(string[] args)
	{
	}

	// Inheritance
	private class FootballGame : Competition {
	  //...
	}

	// Interface definition
	interface IAlarmClock {
	  //...
	}

	// Extending an interface 
	interface IAlarmClock : IClock {
	  //...
	}

	// Interface implementation
	class WristWatch : IAlarmClock, ITimer {
	   //...
	}
}
